Power-operated eraser for electric typewriters



April 22, 1952 M. ALDEN POWER-OPERATED ERASER FOR ELECTRIC TYPEWRITERSFiled Sept. 2, 1949 IIII IN V EN TOR.

W709 Wm M fin new HT TOR/VEKS keys l2.

Patented Apr. 22, 1952 POWER-OPERATED nmsrn FOR ELECTRIC TYPEWRITERSMartha M. Alden, Tulsa, Okla. Application September 2, 1949, Serial No.113,889

mature shaft of the typewriter motor to drive the eraser. V l

A further object is to provide a device of the above-mentioned characterwhich is highly simplified, durable, and quite inexpensive tomanufacture.

Other objects and advantages of my invention will be apparent during thecourse of the following description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are employed to designate like parts throughout thesame,

Figure 1 is a side elevation of an electric typewriter equipped with thepower-operated erasing attachment embodying my invention,

Figure 2 is an enlarged fragmentary horizontal section through a portionof the typewriter casing and showing mechanism forming part of myattachment, and

Figure 3 is a fragmentary vertical section, taken on line 3-3 of Figure2. v

In the drawings, where for the purpose 01 lllustration is shown apreferred embodiment of my invention, the numeral I designates generallyan electric typewriter of conventional construction, and including theusual platen ,II and The typewriter further comprises a housing orcasing I3, having a bottom [4 and a vertical side 15. The typewriter isprovided with a drive motor l6, fixedly secured to the bottom I4,inwardly of and near the side l5 of the casing, and having its armatureshaft l1 extending parallel to the side l5 and toward the front of thetypewriter. A reduction gear box and power takeoff H? for the typewriterdrive is provided forwardly of the motor [6, and this reduction gear boxhas a horizontal shaft l9 connected by a coupling 20 with the armatureshaft [1. The

shaft I9 extends horizontally forwardly of the reduction gear box 18 andcarries a clutch plate 2 l having secured thereto a female conicalclutch element 22 of hard rubber, or the like. when the typewritermaster switch, not shown, is on, the

3 Claims. (Cl. 197 -181) motor armature shaft i1 and reduction gear boxshaft I9 rotate continuously. All of the construction thus far describedis conventional and well-known.

A large rectangular opening 23 is provided in the side [5 of thetypewriter casing, and a removable rectangular cover 24 is detachablyrigid- 1y secured to the side l5, adjacent to the opening 23, by anysuitable means. The cover 24 includes an outer vertical side 25, uponwhich is rigidly mounted a horizontal inwardly extending arm or bracket26, which projects into the typewriter casing, as shown, and carries abearing 21, in axial alignment with the shafts I! and I9. Journalledwithin the bearing 21 for rotation is a horizontal shaft 28, provided atits rear end with axial splines 29, engaging slidably within axialgrooves 30, formed internally in a head 3| of a forwardly and rearwardlyshiftable clutch shaft 32. The clutch shaft 32 has a fixed collar orshoulder 33 secured to it, rearwardly of the head 3| and held againstaxial movement. This shoulder 33 may be a ball bearing, having its innerrace tightly pressed upon the clutch shaft 32 and its outer race freelyrotatable. Secured to the rear end of the clutch shaft 32 for rotationtherewith is a clutch plate 34, carrying a male conical clutch element35 formed of hard rubber, or the like. The clutch shaft 32 is supportedby the shaft 28 and is shiftable axially in both directions upon thesplines 29 for engaging and disengaging the clutch elements 22 and 35.

An inwardly extending upwardly inclined support bracket 36 isrigidlysecured to the cover 24 near its longitudinal center, andgenerally opposite the shoulder or ball bearing 33. The top of thissupport bracket 36 is arranged substantially at the elevation of thehorizontal shaft 32, and pivotally mounted upon the top of the supportbracket 36 for horizontal swinging movement is a clutch actuating leveror plate 31, which extends inwardly beyond the inner end of the supportbracket and is provided with a head 38 having a recess or notch 39 inits inner end, for receiving the outer race of the hearing or shoulder33. The clutch actuating lever 31 extends outwardly through a slot 40,formed in the side 25 of the cover. outwardly of the cover 24, anupstanding vertical bar or plate 4| is rigidly secured at its lower endto the lever 31, and projects above the lever to an elevation near andabove the top of the cover'24, Figure 1. Secured to the top of the bar4! is a spring clip or holder 42, for releasably holding in the verticalposition the housing or casing 43 of a rotary type power driven eraserconnected in apertures 50 and formed in the lever 31 and web 48,respectively. The aperture 50 is disposed longitudinally inwardly of apivot screw 52, which serves to pivotally connect the lever 31 andsupport bracket 36. The spring 49 extends diagonally outwardly upon theright'side I of the lever 31, Figure 2, and tends to bias the head 38 ofthe lever to the right for engaging theclutch element 35 within theelement 22. The

slot 40 has a downwardly offset portion 40' at its right end, Figure 2,within which the lever 31 may engage when the clutch elements aredisengaged, as shown in Figure 2, so that the spring 49 will not be ableto swing the head 38 to the right. The lever 37 is somewhat resilient,and when its outer end is elevated slightly,-it will enter the upperportion of the slot 40 at the left, Figure 2, and the outer end of thelever will swing to the left, Figure 2, under the influence of thespring 49, swinging the head 38 to the right for engaging the clutchelements.

In use, the clutch elements 22 and remain normally disengaged and theclutch shaft 32 will not rotate with the constantly rotating shaft Ill.The eraser casing 43 remains normally in a vertical position adjacent tothe right side 15 of the typewriter casing and held within the resilientspring clip 42. When it is desired to use the power-operated eraser thetypist grasps the casing 43 which serves as a handle and disengages thesame from the clutch 32. When doing this, the typist elevates the freeend of the lever 31 slightly so it may enter the upper portion of theslot and be swung to the left, Figure 2. The spring 59 will cause thisswinging movement as soon as the outer end of the lever 31 is elevatedslightly, and the swinging will therefore be automatic. When it occurs,the head 38 swings to the right and the recess 39 engages the outer raceof the ball bearing 33 and shifts the clutch shaft 32 axially to theright so that the clutch element 35 will engage within the element 22.When this occurs, the clutch shaft 32 will rotate with the shaft 59, andthe shaft 28 will also be driven for driving the flexible drive shaft45. The shaft 35 will in turn rotate the eraser tip 44, and theimplement may be employed for erasing.

When the erasing operation is completed, the typist merely returns thecasing 43 to the clip 42,

pressing the lever 31 rearwardly or to the right,

It is thus seen that I have provided a poweroperated erasing attachmentwhich receives its power from the constantly rotating motor shaft of theelectric typewriter, and I have provided the novel mechanism describedabove for actuating the clutch elements which drive the attachment. Theattachment is very simple, durable and inexpensive to manufacture.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same, and thatvarious changes in shape, size and arrangement of parts may be resortedto, without departing from the spirit of the invention, or the scope ofthe subjoined claims.

Having thus described my invention, I claim:

.1. An erasing attachment for an electric typewriter having a drivemotor including a drive sh aft,-.sa'id. attachment comprising a housingmounted on the typewriter casing, a driven shaft journaled for rotationwithin the housing, said driven shaft being axially movable and in axialalignment Withthe drive shaft, clutch elements cooperatively carried bythe adjoining ends of the shafts, a rotary eraser drivingly connected tosaid driven shaft, an operating lever pivotally mounted-in the housing"and said housing having a slot formed in one-wall thereof through whichthe lever is extended, means connecting the lever to the driven shaftfor shifting said shaft axially to engage the clutch elements, resilientmeans actuating said lever in its movement effecting engagement-of theclutch elements, a holder on the exterior end of the lever, said eraserbein detachably' mountable on said holder and said slot having arecessed endfor lockingly receiving the lever and retaining it in aninoperative position, said lever being held in said recess by the weightof the eraser in the holder.

2. An erasing attachment for an electric typewriter having'a casing anda drive motor including a-drive shaftjcoinpr'ising a driven shaftjournalled for rotation within the casing, said driven shaft beingmovable toward and away from the drive shaft, clutch elementsco-operatively carried by the respective shafts, a rotary eraserdrivingly connected to the driven shaft, an operating lever pivotallymounted in the casing and said casing having a slot formed in one wallthereof through which the lever is extended, means connecting the leverto the driven shaft for shifting the driven shaft toward the drive shaftto engage the clutch elements, resilient means actuating said lever inits movement effecting engagement of the'clutch elements, and a holderon the exterior end of the lever, said eraser being detachably mountableon said holder and said slot having a recessed end for lockinglyreceiving the lever and retaining it in an inoperative position, saidlever being held in the recessed end of the slot by the weight of theeraser in the holder.

3.'An erasing attachment for an electric typewriter having a casing anda drive motor including a drive shaft, said attachment comprising ahousing mounted on the casing, a driven shaft journ'alled for rotationwithin the casing, said driven shaft being axially movable and in axialalignment with the drive shaft, clutch elements co-operatively carriedby the adjoining hands of the shaft, a rotary eraser drivingly connectedto said driven shaft, an operating lever pivoted intermediate its endswithin the casing for swinging movement in a horizontal plane, saidhousing having a slot formed in one wall thereof through which theleveris extended, means connecting the lever to the driven shaft at one endof the lever for shifting said shaft axially to engage the clutchelements responsive to swinging movement of the lever in one direction,a spring connected at its opposite ends to the lever 5 6 and housing,respectively, and arranged to nor- UNITED STATES PATENTS mally exertpressure against the lever tending Number Name Date to swing the leverin said direction to engage the 1,005,352 Stewart Oct-h 10 1911 clutchelements, and a holder on the exterior end 1,360,773 Neel Nov. 30, 1920of the lever, said eraser being detachably niount- 5 1,390072 Eight Apr.7, 1931 able on said holder and said slot having a downwardly offsetportion at one end thereof for lock- FOREIGN PATENTS ingly receiving thelever and releasably engaging N mbe Countr Date the same againstmovement in said direction, said 201,022 Switzerland Jan. 16, 1939 leverbeing held in said downwardly offset por- 10 15,499 Australia se t, 7,1928 tion by the weight of the eraser in the holder.

MARTHA M. ALDEN.

REFERENCES CITED The following references are of record in the 15 fileof this patent:

